1. Technical Field
The present invention relates to an air bag system including an inflatable air bag for, when inflated, restraining a vehicle occupant upon the occurrence of a collision. The present invention is particularly directed to a structure for rapidly changing the temperature of a source of gas such as an inflator for inflating an air bag.
2. Background Art
Inflators for providing gas to inflate an air bag of an air bag system are well known. An inflator is typically designed to operate over a wide ambient temperature range. Although the inflator is designed to operate over a wide ambient temperature range, the inflator performs optimally within a narrow temperature range.
Performance degradation of known inflators increases when the temperature of the inflator is outside of the narrow temperature range. For example, if an inflator is at an extremely high temperature above the narrow temperature range, some gas from the inflator must be released to relieve the increased pressure within the inflator. In contrast, if the inflator is at an extremely low temperature below the narrow temperature range, not enough gas may be provided to inflate the air bag properly.
An inflator may be at an extreme temperature when the vehicle in which the inflator is mounted is initially started. If this is the case, it is desirable to minimize the amount of time the inflator is at the extreme temperature to minimize the time period of potential performance degradation.